This  book  is  Dr  d  below 


IStfccrgtDe  educational  jttonograpl}0 

EDITED  BY  HENRY  SUZZALLO 

PROFESSOR    OF  THE    PHILOSOPHY   OF   EDUCATION 
TEACHERS   COLLEGE,   COLUMBIA    UNIVERSITY 


INDIVIDUALITY 


BY 

EDWARD  L.  THORNDIKE 

PROFESSOR   OF   EDUCATIONAL   PSYCHOLOGY 
TEACHERS    COLLEGE,   COLUMBIA    UNIVERSITY 

2.333^? 


HOUGHTON   MIFFLIN   COMPANY 

BOSTON,    NEW   YORK   AND   CHICAGO 

Cbe  fiiuerjjiue  pre??,  CambriDoe 

a  3 33  O 


COPYRIGHT,    IOII,    BY    HOUGHTON    MIFFLIN   COMPANY 


ALL    RIGHTS    RESERVED 


i  ■  .    •  T 


CONTENTS 

Editor's  Introduction v 

I.   The    Nature    of    Individual    Differ- 
ences   i 

II.   The  Causes  of  Individual  Differences  29 
III.   The   Significance  of    Individual  Dif- 
ferences  ........  49 

Outline 53 


EDITOR'S  INTRODUCTION 

The  teaching  profession  is  showing  signs  of  a 
somewhat  violent  reaction  against  the  uniform- 
ity of  method  that  for  so  long  clutched  and 
mechanized  the  schools.  Long  before  teachers 
realized  the  deadening  effects  of  uniformity, 
there  had  been  many  protests  from  outside  the 
teaching  fold ;  but  they  had  availed  little  in  fo- 
cussing professional  attention.  Parents  had  no- 
ticed that  vigor  and  freshness  were  departing 
from  the  teaching  in  our  public  schools.  Youth 
at  high  schools  and  colleges  had  in  their  own 
way  filed  their  protest  by  turning  from  the  un- 
appealing work  of  classrooms  to  affairs  of  their 
own  invention,  to  school  sports  and  sociability. 
But  the  professional  consciousness  was  not 
deeply  penetrated  until  the  teachers  themselves 
were  caught  in  the  iron  machinery  of  their  own 
making.  When  the  supervision  of  teachers  be- 
came as  inflexible  and  as  unindividual  as  the 
teaching  of  children,  the  problem  of  individu- 
v 


EDITOR'S   INTRODUCTION 

ality  in  education  became  an  acute  professional 
one.  Particularly  was  this  true  in  large  city 
school  systems,  where  the  mere  bigness  of  the 
situation  obscured  both  the  individual  teacher 
and  the  individual  child. 

Of  course  there  have  been  other  forces  con- 
tributing to  this  awakening  to  the  need  of  con- 
serving and  developing  individuality.  Great 
institutional  movements  are  far  too  complex 
to  be  explained  simply,  —  one  set  of  forces  sel- 
dom operates  without  assistance  from  many 
others. 

The  growing  belief  that  the  education  of  all 
children  is  a  public  duty  initiated  difficulties 
that  forced  attention  to  the  need  of  individual 
treatment  of  children.  The  schools  of  an  older 
generation  took  care  of  a  selected  group.  Those 
children  to  whom  a  more  or  less  formal  and  ab- 
stract intellectual  life  appealed  went  to  school 
and  remained  ;  the  others  either  did  not  enter 
school  at  all  or  soon  left  for  more  congenial  em- 
ployment. The  traditional  methods  of  school- 
room procedure  were  adapted  only  to  a  picked 
lot  of  children.  The  effect  of  compulsory  educa- 
vi 


EDITOR'S  INTRODUCTION 

tion  upon  the  school  was  therefore  sweeping. 
All  varieties  of  children  were  compelled  to  at- 
tend a  school  the  traditional  methods  of  which 
fitted  only  a  few.  The  maladjustments  became 
apparent.  The  old  uniform  methods  broke  down 
before  the  needs  of  a  new,  enlarged,  and  more 
varied  population.  Children  were  eliminated 
from  school  or  retarded  in  their  school  careers 
to  such  a  degree  as  seriously  to  indict  the  school 
system.  The  cry  for  individual  adjustment  be- 
came a  shibboleth  among  the  reformers  ;  and  it 
found  a  ready  echo  in  the  city  teacher  who  found 
herself  becoming  a  pedagogical  mechanic  under 
the  uniform  standards  imposed  from  above. 

The  growth  of  cities  also  emphasized  exist- 
ing maladjustments.  The  heterogeneous  school 
populations  of  large  industrial  and  commercial 
centres  embrace  a  wide  distribution  of  eco- 
nomic groups  and  classes.  The  evidence  of  so 
great  variation  in  pupils  in  the  schools  of  these 
cities  helped  the  school  men  of  the  country  to 
realize  that  variety  is  one  of  the  chief  charac- 
teristics of  human  nature.  To  be  sure  the  ob- 
served differences  in  individuals  were  often  due 
vii 


EDITOR'S   INTRODUCTION 

more  to  environment  than  to  original  causes,  and 
were  frequently  more  apparent  than  real ;  the 
effect,  however,  was  even  more  pronounced  than 
if  the  teachers  had  possessed  an  accurate,  scien- 
tific view  of  natural  and  fundamental  variations 
among  men.  The  call  for  special  schools,  smaller 
classes,  and  specialized  methods  of  teaching  was 
prompt,  though  not  always  intelligent.  The  city 
school  system  afforded  an  easy  administrative 
opportunity  for  handling  such  special  classes. 
In  a  congested  population  there  would  be 
enough  deaf  and  dumb,  or  cripples,  or  juvenile 
delinquents,  or  truants,  or  tubercular  children  to 
warrant  the  establishment  of  special  schools  or 
classes.  Hence  the  large  city  easily  furnished  ex- 
amples of  ways  of  providing  for  better  adjust- 
ment to  individuality,  and  became  the  initiator, 
as  well  as  the  pattern,  of  new  movements  of  this 
kind. 

It  is  probable,  too,  that  the  child-study  move- 
ment in  education  gave  assistance  to  the  other 
factors  that  were  breaking  up  the  uniform 
methods  of  the  traditional  school.  It  took  the 
attention  off  certain  ready-made  conceptions  as 
viii 


EDITOR'S  INTRODUCTION 

to  what  the  human  mind  is,  and  turned  it  toward 
the  study  of  the  children  themselves.  The  con- 
crete acts  of  many  children,  observed  under  all 
sorts  of  conditions,  could  not  help  but  stimu- 
late the  growing  belief  that  childhood  has  in- 
finite variety. 

As  a  result  of  these  major  forces,  and  of  some 
other  minor  ones  at  work  in  our  professional 
thought,  the  reaction  against  the  blight  of  uni- 
formity in  teaching  has  deepened.  It  has  ex- 
pressed itself  positively  in  the  demand  for  ad- 
ministrative and  instructional  means  that  will 
produce  an  increased  regard  for  individuality. 
For  the  most  part  this  revolution  —  for  it  has 
been  nothing  less  —  in  point  of  view,  was  a  re- 
bellion of  common  sense  against  an  obvious 
wrong.  It  moved  in  the  right  direction,  but,  as 
is  the  case  when  common  sense  is  the  sole 
guide,  it  advanced  without  much  refinement  of 
either  knowledge  or  methods. 

To  escape  from  the  tyranny  of  traditional  no- 
tions as  to  what  constitutes  an  average  child 
under  average  conditions,  and  to  reach  the  be- 
lief—  general  and  vague  though  it  be  —  that 
ix 


EDITOR'S   INTRODUCTION 

schools  must  be  respecters  of  individuality,  is 
surely  a  sign  of  progress.  But  our  pupils  will 
never  reap  the  full  benefit  of  this  changed  point 
of  view  until  we  know  specifically  to  what  extent 
individuals  vary  and  what  are  the  causes  of  this 
variation  ;  as  well  as  the  particular  practical  im- 
plications of  these  scientific  truths. 

Unfortunately  the  truths  of  such  a  complex 
problem  as  that  of  human  individuality  are  now 
only  in  the  process  of  scientific  reduction.  In  so 
far  as  they  exist  and  may  be  presented  in  re- 
stricted compass,  they  are  summarized  in  the 
volume  here  presented.  But  this  contribution  of 
Professor  Thorndike's  is  significant  for  more 
than  its  incidental  summary  of  known  facts;  for 
it  establishes  a  point  of  view  and  indicates  a 
safe  method  of  approach  to  this  intricate  study 
of  human  nature.  With  ingenious  clarity  and 
brilliant  suggestiveness,  coupled  with  scientific 
caution  and  accuracy,  the  author  has  given  us 
the  fundamental  modes  by  which  uniformities 
and  variations  are  to  be  perceived  in  human 
nature ;  has  stated  their  general  and  specific 
causes  ;  and  has  pointed  out  their  meaning  for  so- 
x 


EDITOR'S  INTRODUCTION 

cial  policy.  Even  the  casual  reader  of  this  mono- 
graph cannot  fail  to  appreciate  its  bearings  upon 
much  that  passes  as  truth  in  both  popular  belief 
and  professional  theory. 


INDIVIDUAT  ITY 


THE   NATURE  OI    INDIVIDUAL    DIFFERENCES 

-2.3330 
The  life  of  a  man  is  a  double  series  —  a  series  of 

effects  produced  in  him  by  the  rest  of  the  world, 
and  a  series  of  effects  produced  in  that  world  by 
him.  (A  man's  make-up  or  nature  equals  his  ten- 
dencies to  be  influenced  in  certain  ways  by  the 
world  and  to  react  in  certain  ways  to  it. I  To  de- 
scribe even  one  man's  intellect  and  character 
fully,  at  even  any  one  time,  it  would  be  neces- 
sary to  list  all  the  world's  happenings  that  he 
might  possibly  encounter,  and  to  state  in  each 
case  how  he  would  feel  and  think  and  act  in 
response  to  that  happening. 

If  we  could  thus  adequately  describe  each  of  a 
million  human  beings, — if,  for  each  one,  we  could 
prophesy  just  what  the  response  would  be  to  every 
possible  situation  of  life, —  the  million  men  would 
be.  found  to  differ  widely.  Probably  no  two  out 
I 


INDIVIDUALITY 

of  the  million  would  be  so  alike  in  mental  nature 
as  to  be  indistinguishable  by  one  who  knew  their 
entire  natures.  Each  has  an  individuality  which 
marks  him  off  from  other  men.  Each  has  not 
only  a  mind,  the  mind  of  the  human  species,  but 
also  his  own,  specialized,  particular,  readily  dis- 
tinguishable mind.  Even  in  bodily  nature,  in- 
deed, men  differ  so  much  that  it  would  be  hard 
to  find,  amongst  a  million,  two  whose  features  are 
just  alike,  who  are  equally  susceptible  to  every 
disease,  who  have  identical  bodily  habits.  The 
differences  in  intellect  and  character  are  far 
greater. 

We  may  study  a  human  being  in  respect  to  his 
common  humanity,  or  in  respect  to  his  individ- 
uality. In  other  words,  we  may  study  the  fea- 
tures of  intellect  and  character  which  are  common 
to  all  men,  to  man  as  a  species ;  or  we  may  study 
the  differences  in  intellect  and  character  which 
distinguish  individual  men. 

The  study  of  the  facts  and  laws  applicable  to 
all  men  by  virtue  of  their  common  humanity 
gives  education  its  fundamental  rules  for  the  con- 
trol of  changes  in  intellect  and  character.  The 
2 


NATURE  OF  INDIVIDUAL  DIFFERENCES 

study  of  the  facts  and  laws  of  individual  differ- 
ences enables  us  to  apply  these  principles  economi- 
cally in  the  case  of  each  individual  whom  we  seek 
to  educate. 

In  studying  individual  differences,  it  is  cus- 
tomary to  reduce  the  infinitude  of  tendencies  to 
think  and  feel  and  act  in  certain  ways  in  response 
to  the  varied  situations  which  life  offers,  to  the 
more  general,  and  so  fewer,  tendencies  which 
the  psychologist  calls  abilities,  interests,  habits, 
qualities  of  mind,  or  mental  traits.  Thus  the 
hundreds  of  connections  between  the  situations 
represented  by  all  the  possible  problems  in  ad- 
dition and  the  responses  represented  by  all  their 
solutions,  are  reduced  to  the  one  trait,  "ability 
to  add."  Thus  the  many  inborn  connections  be- 
tween, on  the  one  hand,  seeing  and  touching 
blocks,  sand,  strings,  wire,  stones,  water,  and 
other  material  objects,  and  on  the  other  hand 
examining,  poking,  pulling,  putting  together, 
taking  apart,  forming  and  re-forming  those  ob- 
jects, are  comprised  in  the  one  trait,  "  the  instinct 
of  constructiveness  "  or  "the  interest  in  manipu- 
lation." Thus  by  such  a  term  as  "  memory  for  fig- 
3 


; 


INDIVIDUALITY 

ures  "  we  refer  to  the  permanence  of  many  con- 
nections, —  the  thought  of  a  battle  with  its  date, 
the  thought  of  a  person  with  his  address  or  tele- 
phone number,  the  thought  of  a  city  with  its  num- 
ber of  inhabitants. 

f  Individuals  are  commonly  considered  as  differ- 
ing in  respect  to  such  traits  either  quantitatively 
or  qualitatively,  either  in  degree  or  in  kind.  A 
uantitative  difference  exists  when  the  individ- 
uals have  different  amounts  of  the  same  trait. 
Thus,  "John  is  more  attentive  to  his  teacher  than 
James  is,"  "Mary  loves  dolls  less  than  Lucy 
does,"  "A  had  greater  devotion  to  his  country 
than  B  had,"  are  reports  of  quantitative  differ- 
ences, of  differences  in  the  amount  of  what  is 
assumed  to  be  the  same  kind  of  thing.  A  qual- 
itative difference  exists  when  some  quality  or  trait 
possessed  by  one  individual  is  lacking  in  the 
other.  Thus,  "Tom  knows  German,  Dick -does 
not,"  "A  is  artistic,  B  is  scientific,"  "  C  is  a  man 
of  thought,  D  is  a  man  of  action,"  are  reports  of 
the  facts  that  Tom  has  some  positive  amount 
or  degree  of  the  trait  "  knowledge  of  German  " 
while  Dick  has  none  of  it,  that  A  has  some  posi- 
4 


NATURE  OF  INDIVIDUAL  DIFFERENCE^ 

tive  amount  of  ability  and  interest  in  art  while 
B  has  zero,  whereas  B  has  a  positive  amount  of 
ability  and  interest  in  science,  of  which  A  has 
none,  and  so  on. 

A  qualitative  difference  in  intellect  or  charac- 
ter is  thus  really  a  quantitative  difference  wherein 
one  term  is  zero,  or  a  compound  of  two  or  more 
quantitative  differences.  All  intelligible  differ- 
ences are  ultimately  quantitative.  The  difference 
between  any  two  individuals,  if  describable  at  all, 
is  described  by  comparing  the  amounts  which  A 
possesses  of  various  traits  with  the  amounts  which 
B  possesses  of  the  same  traits.  In  intellect  and 
character,  differences  of  kind  between  one  in- 
dividual and  another  turn  out  to  be  definable, 
if  defined  at  all,  as  compound  differences  of  de- 
cree. 

/'  If  we  could  list  all  the  traits,  each  representing 
some  one  characteristic  of  human  nature,  and 
measure  the  amount  of  each  of  them  possessed 
by  a  man,  we  could  represent  his  nature  —  read 
his  character —  in  a  great  equation.  John  Smith 
would  equal  so  many  units  of  this,  plus  so 
many  units  of  that,  and  so  on.  Such  a  mental 
5 


I  INDIVIDUALITY 

inventory  would  express  his  individuality  conceiv- 
ably in  its  entirety  and  with  great  exactitude. 

No  such  list  has  been  made  for  any  man,  much 
less  have  the  exact  amounts  of  each  trait  pos- 
sessed by  him  been  measured.  But  in  certain  of 
the  traits,  many  individuals  have  been  measured  ; 
and  certain  individuals  have  been  measured,  each 
in  a  large  number  of  traits.  I  shall  state  first 
some  of  the  more  important  results  of  the  mea- 
surements of  individual  differences  in  the  case  of 
single  traits,  differences  in  the  amount  of  the 
same  kind  of  quality  or  thing. 

INDIVIDUAL  DIFFERENCES  IN  SINGLE  TRAITS 

It  is  useless  to  recount  the  traits  in  which  men 
have  been  found  to  differ.  For  there  is  no  trait 
in  which  they  do  not  differ.  Of  course  if  the 
scale  by  which  individuals  are  measured  is  very 
coarsely  divided,  their  differences  may  be  hidden. 
If,  for  example,  ability  to  learn  is  measured  on  a 
scale  with  only  two  divisions,  (i)  "ability  to  learn 
less  than  the  average  kitten  can"  and  (2)  "  ability 
to  learn  more  than  the  average  kitten  can,"  all 
men  may  be  put  in  class  two,  just  as  if  their 
6 


DIFFERENCES  IN   SINGLE  TRAITS 

heights  were  measured  on  a  scale  of  one  yard, 
two  yards,  or  three  yards,  nearly  all  men  would 
alike  be  called  two  yards  high.  But  whenever 
the  scale  of  measurement  is  made  fine  enough, 
differences  at  once  appear. 

Their  existence  is  indubitable  to  any  impartial 
observer.  The  early  psychologists  neglected  or 
failed  to  see  them  precisely  because  the  early 
psychology  was  partial.  It  believed  in  a  typical 
or  pattern  mind,  after  the  fashion  of  which  all 
minds  were  created,  and  from  which  they  differed 
only  by  rare  accidents.  It  studied  "  the  mind," 
and  neglected  individual  minds.  It  studied  "  the 
will "  of  "  man,"  neglecting  the  interests,  im- 
pulses, and  habits  of  actual  men. 

The  differences  exist  at  birth  and  commonly 
increase  with  progress  toward  maturity.  Individ- 
uality is  already  clearly  manifest  in  children  of 
school  age.  The  same  situation  evokes  widely 
differing  responses  ;  the  same  task  is  done  at 
differing  speeds  and  with  different  degrees  of 
success  ;  the  same  treatment  produces  differing 
results. 

There  can  be  little  doubt  that  of  a  thousand 

7 


INDIVIDUALITY 

ten-year-olds  taken  at  random,  some  will  be  four 
times  as  energetic,  industrious,  quick,  courage- 
ous, or  honest  as  others,  or  will  possess  four 
times  as  much  refinement,  knowledge  of  arith- 
metic, power  of  self-control,  sympathy,  or  the  like. 
It  has  been  found  that  amongst  children  of  the 
same  age  and,  in  essential  respects,  of  the  same 
home  training  and  school  advantages,  some  do  in 
the  same  time  six  times  as  much,  or  do  the  same 
amount  with  only  one  tenth  as  many  errors. 

The  ways  in  which  and  the  extent  to  which  in- 
dividuals differ  in  mental  traits  can  be  best  un- 
derstood by  considering  the  Distribution  of  the 
trait,  that  is,  the  number  of  individuals  possess- 
ing each  degree  of  it.  For  example,  the  distribu- 
tion of  stature  in  American  boys  ten  and  a  half 
years  old  is  roughly  as  follows. 

Out  of  iooo  boys,  there  are :  — 


Between  109  and  113  centimetres  tall,      2  boys. 


«    „3  i 

117     " 

"   5  boys 

117  « 

'  121     " 

41  25  boys. 

"    121  ' 

'  125 

"  97  boys. 

125  ' 

'129     " 

"  199  boys. 

"    129  ' 

'  133 

"  255  boys. 

DIFFERENCES  IN  SINGLE  TRAITS 

Between  133  and  137  centimetres  tall,  228  boys. 
"         137     "     141  "  "   126  boys. 

"         141     "     145  "  "     49  boys. 

"         145     "     149  "  "ii  boys. 

"         149     "     153  "  "       4  boys. 

The  facts  of  this  table  become  clearer  to  the 
eye  if,  instead  of  the  numbers  2,  5,  25,  97,  etc., 


;/ 


UJCrv    *-  «f  trj  ill  IIS  129  4D  /)}  ***  *,  j  Mg  ,si  c* 

Fig.  1.   The  Distribution  of  Stature  of  American  Boys  ioi  yrs.  old. 


we  draw  1000  little  lines  as  in  Figure  1,  letting 
each  line  stand  for  one  boy. 

It  is  customary  to  represent  the  amounts  of 
the  trait  not  by  a  verbal  statement  like  "  from 
109  cm.  to  113  cm.,"  but  by  a  distance  along  a 
scale  from  the  point  on  the  scale  marked  109  cm. 
to  the  point  marked  113  cm.;  and  to  represent 
9 


INDIVIDUALITY 

the  number  of  individuals  who  possess  that  de- 
gree of  the  trait  not  by  the  number  of  lines,  but 
by  the  size  of  an  area.  The  previous  table  then 
becomes  Figure  2. 

Such  a  figure  is  called  the  Surface  of  Distribu- 
tion of  the  trait.  Such  distribution  tables  or  sur- 
faces are,  so  to  speak,  the  language  of  individual 


Fig.  s.   The  Distribution  of  Stature  of  American  Boys  ioj  yrs.  old, 
the  relative  frequencies  being  measured  by  area. 


psychology.  They  tell  us  what  the  "type"  or 
"norm"  or  common  tendency  is,  how  and  how 
far  individuals  vary  from  the  type,  whether  there 
are  secondary  or  sub-types,  how  "abnormal"  any 
given  degree  of  the  trait  is,  and  the  like.  For  in- 
stance, in  the  case  of  our  illustration,  it  is  clear 
10 


DIFFERENCES   IN  SINGLE  TRAITS 

that  there  is  one  central  tendency,  the  typical 
height  for  a  boy  of  this  age  being  about  133  cm. ; 
that  slight  individual  variations  from  the  type 
are  very  numerous,  but  that  large  variations 
from  it  are  very  rare ;  that  the  variations  are 
continuous,  individuals  being  found  of  every 
height  from  1 10  cm.  to  over  150  cm. ;  that  a  boy 
over  149  cm.  tall  at  the  age  of  ten  and  a  half 
would  be  abnormal  in  the  sense  that  he  would 
occur  only  once  in  two  hundred  and  fifty  times, 
but  would  not  be  abnormal  in  the  sense  of  being 
removed   from   ordinary  children  by  a  distinct 

gap. 

All  thought  about  individual  differences  in 
single  traits  should  be  carried  on  in  terms  of 
such  distribution  tables  or  surfaces,  each  derived 
from  the  actual  measurement  of  a  large  and 
representative  group  of  individuals.  It  is  mislead- 
ing to  form  opinions  from  casual  observations  of 
human  nature  without  accurate  measurements. 
For  casual  observation  is  struck  by  extreme, 
odd,  exciting,  and  desired  facts.  It  notes,  for 
example,  that  two  railroad  wrecks  occurred  at 
the  same  day  and  hour,  that  it  has  not  rained  for 
n 


INDIVIDUALITY 

two  months,  that  Walter  Scott  was  thought  dull 
as  a  boy,  that  the  rule  of  the  Republican  party 
has  greatly  increased  (or  decreased)  prosperity. 
It  is  misleading  to  judge  from  measurements 
of  a  few  individuals.  For  their  meaning  can  be 
rightly  seen  only  by  comparison  with  the  total 
distribution  in  respect  to  the  trait  in  question. 
In  theory  and  in  practice,  we  must  think  of  an 
individual  in  any  one  trait  not  only  as  he  is  in 
and  of  himself,  but  as  he  is  in  relation  to  all  men, 
—  as  one  variation  amongst  others  in  the  total 
distribution  in  respect  to  that  trait.  There  is  in- 
deed no  one  habit  of  thought  about  human  na- 
ture more  important  for  the  understanding  of 
individuality  than  the  habit  of  thinking  of  the 
different  amounts  or  degrees  of  each  single  qual- 
ity or  trait  as  distances  along  a  scale,  and  of 
men  and  women  as  distributed  along  that  scale 
each  at  his  proper  point. 

The  study  of  such  distributions  in  the  case  of 
qualities  of  intellect  and  character,  has  brought  to 
light  two  facts,  both  at  variance  with  common  opin- 
ion and  both  of  importance  for  the  practical  con- 
trol of  individuals  by  schools,  laws,  books,  and  the 

12 


DIFFERENCES  IN   SINGLE  TRAITS 

like.  First,  the  variations  in  any  single  trait  are 
usically  continuous.  Second,  the  variations  usually 
cluster  around  one  and  only  one  type. 

The  continuity  of  variations  appears  in  every 
trait  that  has  so  far  been  measured.  Children 
rarely  or  never  fall  into  distinct  clas'ses  with 
gaps  between,  —  bright,  average,  and  dull,  sane 
and  insane,  visualizers  and  non-visualizers,  color- 
seeing  and  color-blind,  and  the  like.  On  the  con- 
trary, between  the  least  and  the  greatest,  the 
best  and  the  worst,  every  degree  is  represented. 

The  clustering  around  one  type,  though  not 
perhaps  as  universal  as  the  continuity  of  varia- 
tions, is  also  to  be  expected,  save  under  certain 
special  conditions  in  the  causes  that  produce  the 
trait.1  The  true  state  of  affairs  is  that  shown  by 
such  distributions  as  those  of  Figure  3,  not  by 
such  as  those  of  Figure  4.  We  must  not  be  mis- 
led, by  the  habit  of  thinking  in  words,  into  the 
false  belief  that  individualities'  are  grouped  into 

1  The  discussion  of  these  causes  is  somewhat  intricate  and 
out  of  place  in  this  brief  exposition.  The  reader  will  find  the 
essential  facts  in  the  author's  Educational  Psychology,  pp.  1 50- 
170. 

13 


INDIVIDUALITY 

classes  to  fit  those  words.  The  usages  of  language 
are  rarely  competent  to  express  the  real  fact  of 
variations  clustering  around  one  type  or  mode 


JK 


Fig.  3.   Actual  Distributions  found  in  Mental  Measurements. 

A.  Reaction  time  of  college  freshmen. 

B.  Efficiency  in  marking  A's  on  a  sheet  of  printed  capitals;  12-year- 
old  boys. 

C.  Memory  of  digits  of  women  students. 

D.  Efficiency  in  writing  the  opposites  of  words  ;  12-year-old  boys. 

and,  as  the  variation  increases,  occurring  in  ever- 
diminishing  frequency.  That  we  call  children 
good  or  bad  does  not  mean  that  there  are  two 

H 


DIFFERENCES  IN  SINGLE  TRAITS 


types  or  modes  of  character.  That  the  words  "de- 
ficient," "normal,"  and  "superior"  are  used  of 
any  trait  is  no  proof  that  individuals  in  that  trait 
show  a  separation  into  three  groups,  all  in  one 
group  being  much  like  one  another  and  little  like 
any  of  those  in  the  other  groups. 


l-k 


A 


I 


L^f 


Fig.  4.   Distributions  around   Several    Distinct  Types,  such   as  are 
not  commonly  found  to  exist. 

We  must  learn  to  think  of  the  degree  or 
amount  of  any  quality  in  an  individual  not  by  an 
adjective,  but  by  a  numerical  amount.  We  must 
keep  all  men  in  one  class  or  species,  or  divide 
them  into  two,  three  or  more  classes  or  species, 
according  to  the  way  they  are  in  fact  divided,  not 
15 


INDIVIDUALITY 

according  to  rhetorical  convenience.  In  the  great 
majority  of  single  traits,  there  is  only  one  type  or 
mode,  so  that  any  division  into  distinct  classes 
according  to  the  amount  of  the  trait  is  arbitrary. 
The  distribution  being  as  in  Figure  5,  it  is  equally 
possible  to  divide  individuals  into  two,  three,  four, 
five,  six,  seven,  eight,  or  eight  hundred  classes; 
and  for  any  given  number  of  classes  one  may  put 


Fig.  5.    A  Generalized  Picture  of  the  Form  of  Distribution  to  which 
the  Actual  Distributions  approximate. 

the  dividing  lines  in  one  place  as  well  as  another. 
Consequently  classifications  of  individuals  with 
respect  to  the  amount  of  any  single  trait  are  al- 
most always  useless  if  not  misleading.  The  story 
is  to  be  told,  not  by  a  series  of  names,  but  by  a 
surface  of  distribution  erected  on  a  numerical 
scale. 

Turning  again  to  Figure  3,  one  notes  that  all 
16 


DIFFERENCES  IN  SINGLE  TRAITS 

the  distributions  there  shown  have,  as  a  common 
feature,  the  great  frequency  of  mediocrity  and 
the  rareness  of  both  specially  low  and  specially 
high  degrees  of  a  trait.  Approximately  this  is  the 
rule  for  the  original  individualities  of  mankind. 
Approximately  this  remains  the  rule  for  many 
traits  throughout  the  course  of  life  and  its  training. 
In  many  traits  a  very  small  difference  in  ability 
or  attitude  near  the  middle  point  of  the  scale  in- 
cludes a  great  many  individuals.  This  fact  explains 
much  in  human  behavior.  For  instance,  social  and 
political  movements  are  often  instigated  by  indi- 
viduals who  are  at  the  extremes  of  the  scale  with 
respect  to  some  doctrine.  But  the  deciding  votes 
are  almost  always  cast  by  individuals  who  have  no 
very  pronounced  inclination  in  either  direction. 
The  attractiveness  of  some  hero,  the  suggestive 
power  of  some  battle-cry,  an  affront  to  the  sense  of 
fair  play,  a  year  of  hard  times,  a  moderate  expendi- 
ture of  money,  even  the  mere  desire  for  novelty, 
may  turn  the  balance,  because  only  a  slight  addi- 
tion to  the  attractiveness  of  one  proposal  is 
needed  to  move  a  great  number  of  those  near  the 
point  of  neutrality.  To  overturn  a  large  majority 
17 


INDIVIDUALITY 

requires  only  a  small  change  in  opinion.  A  slight 
improvement  in  teaching  may  make  a  misunder- 
stood point  clear  to  a  large  percentage  of  the  class. , 

The  facts  that  have  been  stated  concerning  the 
distribution  of  single  traits  teach,  with  respect  to 
their  educational  control,  that  any  method  which 
is  the  best  possible  for  those  of  one  degree  of  a 
trait  cannot  be  the  best  possible  for  all  individu- 
als. Nor  will  two  or  three  varieties  of  treatment 
suffice  to  educate  all  in  the  best  way.  Variations 
in  human  nature  are  wide  and  continuous,  so  that 
theoretically  treatment  also  must  vary  much  and  . 
continuously.  / 

It  is  not  possible  with  ordinary  facilities  thus  to 
give  each  individual  in  each  trait  the  best  possi- 
ble treatment,  but  knowledge  of  the  amount  and 
distribution  of  variations  will  prevent  certain 
blunders.  For  example,  a  division  into  three 
groups  is  usually  very  much  preferable  to  a  divi- 
sion into  two  groups,  but  the  gain  by  adding  a 
fourth  is  far  less.  One  change  in  school  practice 
to  make  it  more  conformable  to  individual  differ- 
ences is  entirely  practicable.  Since  the  variations 
in  any  trait  are  so  wide,  a  pupil  should  always  be 
18 


COMBINATIONS  OF  TRAITS 

measured,  not  only,  as  now,  by  his  ability  in  com- 
parison with  his  fellows,  but  also  by  his  improve- 
.  ment  over  his  own  past  record.  School  marks 
should  be  on  absolute*  as  well  as  relative  scales.1 
A  child  should  be  given  a  measure  of  cha,7ige  as 
well  as  of  present  inferiority  or  superiority  to 
some  standard  in  the  teacher's  mind. 

INDIVIDUAL  DIFFERENCES  IN  COMBINATIONS 
OF  TRAITS 

The  variety  of  human  nature  possible  when 
one  man  is  compared  with  others  in  respect  to 
all  possible  traits  is  practically  infinite.  Even  if 
man's  nature  included  only  five  traits,  a,  b,  c,  d, 
and  e,  and  even  if  each  of  these  existed  in  only 
N  five  degrees,  I,  2,  3,  4,  and  5,  there  could  be  over 
three  thousand  (3125,  to  be  exact)  varieties  of 
men.  With  hundreds  of  traits,  each  represented 
in  hundreds  of  degrees,  the  varieties  possible  are 
practically  infinite.  All  the  principles  involved 
can,  however,  be  understood  in  a  simplified  case 
such  as  that  of  the  five  traits,  each  appearing  in 

1  For  a  description  of  such  an  absolute  scale  see  the  author's 
"Handwriting,"  Teachers  College  Record,  March,  1910. 

19 


INDIVIDUALITY 

five  degrees.  In  the  simple  case  any  one  individ- 
ual would  be  represented  by  an  equation  such 
as : — 

W.  Roberts  =  2a  -\-  zb  +  $c  -f  id  -\-  ie, 
John  Smith  =  1  a  -f-  afi  -\-  zc  -f-  sd  -\-  \e, 
H.  Thomas   =  40  +  lb  -\-  \c  -f-  id -\-  ie, 

or,  more  clearly,  by  a  series  of  points  on  the  five 
scales  for  the  five  traits  as  in  Figure  6. 


0 

1                 a 

3                          4 

6 

8~~ — . ___    Ft 

__.. -  ""  1 

T                         R"---- 
j 

_-—-~"""J'  8 

TV.                   8" — 

""—— — -— __- 

'    B 

H " 

S 

Fig.  6.  Three  Individuals,  R,  S,  and  T,  each  measured  in  the  case 
of  Five  Traits,  a,  d,  c,  d,  and  et  as  possessing  1,  2,  3,  4,  or  5  de- 
grees thereof. 

Over  three  thousand  varieties  are  possible,  but 
they  need  not  all  occur.  For  example,  suppose 
that  the  amount  of  trait  a  that  an  individual  pos- 
sessed was  so  related  with  the  amounts  of  b,  c,  d, 
and  e  that  he  possessed,  that  if  he  had  2a  he 
would  have  also  2b,  2c,  2d,  and  2e,  while  if  he 
20 


COMBINATIONS  OF  TRAITS 

had  4a  he  must  have  4b,  4c,  4d,  and  4c,  and 
similarly  for  \a,  3#,  and  $a.  Then  the  only  varie- 
ties of  individuals  that  could  exist  would  be :  — 

Some  who  were  la  -\-  \b -\-  \c-\-id  -\-  it, 
u         m        «     2fl_|_2£_|_  2c-\-2d-\-2e, 

and  so  on,  five  varieties  in  all,  shown  in  Figure 
7.  Or  suppose  that  an  individual  having  5^  could 


0                   18                   3 

4 

6 

T" 

¥ 

ff          

1 

1 

1 

1 

1 
1 

'                   ¥                   ' 

1 

d 

1 

1 

1 

¥                   ' 

T 

T 
1 

« 

t 

I * 1 

H 

j. 

1 

B 

Fig.  7. 

never  have  less  than  3  of  b,  c,  d,  and  e.  Then 
such  individualities  as  — 

Sa  +  2b  +  4^  +  3//  +  5*, 

5<*  +  5<>+  1* +  4^+3*1 
and  the  like  could  not  exist.  The  kind  of  varie- 
ties that  can  exist  will  then  express  the  relations, 
or,  as  they  are  commonly  called,  the  correlations, 
between  the  amounts  of  the  five  traits,  that  is, 
21 


INDIVIDUALITY 

the  extent  to  which  the  amount  of  one  trait 
possessed  by  an  individual  is  bound  up  with  the 
amount  which  he  possesses  of  some  other  trait. 
This  is  as  true  for  five  hundred  traits  as  for  five, 
and  for  an  infinite  number  of  degrees  of  each  as 
for  five  degrees.  What  kind  of  individuals  there 
will  be,  and  what  proportion  there  ivill  be  of  each 
kind,  is  a  result  of  the  distribution  of  individuals 
in  single  traits  and  of  the  correlations  of  the 
traits.  To  this  fact  we  shall  soon  need  to  return. 
Confronted  by  the  infinite  variety  of  total  hu- 
man natures,  thinkers  have  hoped  to  find  certain 
types, — the  genius,  the  insane,  the  criminal,  the 
defective,  the  artist,  the  man  of  affairs,  and  the 
like,  —  such  that  all,  or  at  least  many,  individuals 
would  belong  under  one  or  another  of  these  types. 
A  type  represents  some  particular  combination 
of  amounts  of  the  list  of  human  traits.  For  ex- 
ample,  suppose  the  list  of  traits  to  be  a,  b,  c,  d, 
and  e,  and  the  degrees  of  each  to  range  from  o 
to  10.  Then 

(I)  2a  -f-  56  -f-  sc  +  &/  +  ice, 
(II)  10a  -f-  2b  -f-  2c  -J-  1  d -\-  oe, 
and  (III)  /\a  -+-  afi  -\-  4c  -}-  6d -f-  5^ 
22 


COMBINATIONS  OF  TRAITS 

would  be  possible  types.  They  are  represented 
graphically  in  Figure  8. 

Now  such  individuals  as:  — 

(i)  \a  +  s,b  +  5^  +  9^  +  9*. 
or  (2)  30  -|-  4<5  +  5^  +  8^  +  IO*> 
or  (3)  2a  -j-  5^  +  6f  -J-  8</  -f-  10*, 

obviously  vary  little  from  Type  I,  but  much  from 
Type  II  or  Type  III. 

Ol  23456789        10 


^4^_  ------  ~ 

i           "1 

1         i 

,'                     /                ^^ 

Fig.  8.  Three  Possible  Types. 

Such  individuals  as  — 

(4)  \oa  -\-  lb  -\-  2c  -\-  od  -\-  ze, 

(5)  9a -\-  2b  -\-  2c  -\-  2d  -{-  le, 

vary  little  from  Type  II,  but  much  from  Type  I 
or  III.  Consider  similarly  such  individuals  as  :  — 

(6)  $a+  sb  +  V  +  M+  y, 

(7)  2a  +  4b  +  ¥  +  S<*  +  4'- 

23 


INDIVIDUALITY 

These  facts  are  easily  seen  in  Figure  9,  which 
represents  Types  I,  II,  and  III  and  individuals  1 
to  7. 

The  customary  view  has  been  that  "types,"  or 
particular  combinations  of  amounts  of  human 
traits,  could  be  found  so  that  any  individual  would 
be  much  like  some  type  and  much  less  like  any 


8        9 


10 


*  *  ~  .7?*"* 

r*»    _»»——"  ~~  **  **  *" 

\ 
\ 

>C^^-._ 

■/  7      "Ss, 

Fig.  9.   The  Three  Types  of  Fig.  8,  and   Seven   Individuals,   each 
conforming  closely  to  one  or  another  of  the  three  types. 

of  the  others.  But  no  one  has  succeeded  in  find- 
ing such  types,  and  the  more  clearly  the  sup- 
posed types  are  defined,  the  surer  it  becomes 
that  intermediate  conditions,  equally  like  several 
of  the  types,  exist  in  great  numbers.  Either  new 
types  have  to  be  added  until  there  are  so  many 
that  one  may  as  well  let  each  individual  be  his 
24 


COMBINATIONS  OF  TRAITS 

own  type ;  or  the  number  of  individuals  not  fall- 
ing readily  under  any  type  is  so  large  that  the 
attempt  to  classify  men  by  them  hinders  rather 
than  helps  thought  and  practical  control.  Only 
very  rarely  can  anything  approaching  at  all 
closely  to  an  accurate  and  adequate  account  of  a 
man's  individuality  be  given  by  the  statement 
that  he  is  of  this  or  that  "type." 

In  fact,  there  is  much  reason  to  believe  that 
human  individualities  do  not  represent  ten  or  a 
hundred  or  a  thousand  types,  but  either  one 
single  type  or  as  many  types  as  there  are  individ- 
uals, according  to  whether  the  thinker  wishes 
to  emphasize  the  mode  around  which  they  vary 
or  the  exact  nature  of  their  variations  from  it. 
By  this  view  the  effort  to  assign  individuals  to  a 
number  of  classes,  as  we  assign  animals  to  the 
classes  "mammals,"  "reptiles,"  "amphibians," 
"  fishes,"  etc.,  is  doomed  to  failure  or  incompet- 
ence. The  first  duty  of  the  thinker  is  to  learn 
the  constitution  of  the  one  type,  man.  His  sec- 
ond duty  is  to  learn  each  individual's  variation 
from  this  common  humanity.  In  theory  it  means 
that  man  is  mentally,  as  much  as  physically,  one 
25 


INDIVIDUALITY 

species.  In  practice  it  means  that  each  individ- 
ual must  be  considered  by  himself. 

It  certainly  is  the  case  that  almost  all  of  the 
detailed  classifications  of  individuals  in  accord 
with  the  multiple-type  theory  are  either  useless 
or  misleading.  The  commonest  element  in  such 
classifications  is  the  supposed  principle  of  com- 
pensation or  balance,  whereby,  for  example,  a 
"quick  but  careless"  type  is  contrasted  with  a 
"slow  but  sure"  type;  or  an  "easy  learning, 
quickly  forgetting  "  type  is  contrasted  with  the 
slow  learner  who  retains  long;  or  efficiency  in 
thought,  efficiency  in  action,  and  delicacy  in  sen- 
timent are  supposed  to  be  exclusive,  each  of  the 
other  two.  Such  types,  presupposing  relations  of 
compensation  between  intrinsically  desirable 
traits,  are  almost  certainly  illusory. 

All  trustworthy  studies  so  far  made  of  the  re- 
lations between  the  amounts  of  desirable  single 
traits  in  the  same  individual  agree  in  finding  di- 
rect or  "positive"  relations  between  such  traits. 
Having  a  large  measure  of  one  good  quality  in* 
creases  the  probability  that  one  will  have  more 
than  the  average  of  any  other  good  quality.  He 
26 


COMBINATIONS  OF  TRAITS 

who  can  learn  better  than  the  average  through 
the  eyes,  tends  to  learn  better  than  the  average 
through  the  ears  also  ;  he  who  can  attend  to  one 
thing  better  than  all  other  men,  will  be  able  to 
attend  to  many  things  at  once  or  in  rapid  succes- 
sion better  than  most  of  them.  Artistic  ability,  asx 
in  music,  painting,  or  literary  creation,  goes  with 
scientific  ability  and  matter-of-fact  wisdom.  The 
best  abstract  thinker  will  be  above  the  average  in 
concrete  thought  also.  The  rapid  workers  are  the 
more  accurate.  Intellectual  ability  and  moral 
worth  hang  together. 

The  correlations  are,  of  course,  not  perfect.  A 
large  degree  of  superiority  in  one  desirable  trait 
may  involve  only  a  slight  superiority  in  many 
others.  And  since  the  relations  vary  enormously 
amongst  individuals,  a  person  highly  gifted  in  one 
respect  will  often,  though  not  usually,  be  very  in- 
ferior in  others. 

The  description  which  I  have  given  of  the  va- 
rieties of  total  human  nature  doubtless  seems  to 
the  reader  to  be  far  from  clear.    We  have  seen 
that  millions  upon  millions  of  different  conditions 
27 


INDIVIDUALITY 

of  traits  may  exist ;  that  a  large  fraction  of  them 
do  exist ;  that  they  do  not  divide  naturally  into  dis- 
tinct types,  but  probably  vary  around  one  type ; 
and  that  efficiency  in  one  respect  is  positively  cor- 
related with  efficiency  in  others.  We  may  add  that, 
in  general,  the  greater  the  variation  from  the 
one  common  type  of  "the  ordinary  individual," 
the  rarer  it  is.  But  we  have  failed  to  get  a  neat, 
handy  summary  of  the  varieties  of  mankind.  Their 
multitudinous  complexity  and  richness  remains  to 
baffle  the  mind. 

The  fact  is  that  a  simple,  orderly,  tidy  chart  of 
human  geography  would  be  sure  to  be  a  false  one, 
and  that  until  inventories  of  the  amounts  of  hun- 
dreds of  traits  are  made  for  many  individuals,  we 
have  no  right  to  construct  such  a  chart  of  any 
sort.  Even  by  original  nature,  intellect  and  char- 
acter are  enormously  diversified,  and  differences 
in  training  add  new  complexities.  For  the  pre- 
sent each  individual's  equation  must  be  written 
out  as  a  result  of  a  direct  examination  of  his 
whole  make-up,  not  inferred  from  a  few  symp- 
toms, plus  a  hasty  general  theory  of  individuality. 


II 

THE   CAUSES  OF  INDIVIDUAL  DIFFERENCES 

No  competent  thinker  to-day  doubts  that  every 
slightest  feature  of  every  man's  individuality  has 
a  natural  cause.  Men  and  women  are  always  what 
they  are  for  some  reason  ;  and  the  reason  is  some 
fact  in  the  real  world.  No  mere  chances,  fairies, 
or  demons  impregnate  a  human  mind  with  its  pe- 
culiarities. Each  comes  as  a  result  of  natural  law, 
and  could  be  predicted  by  a  perfect  intelligence 
in  possession  of  all  the  facts. 

Sex,  remote  ancestry  or  race,  immediate  an- 
cestry or  family,  growth  or  maturity,  and  that 
total  of  forces  operating  on  a  man's  nature  which 
we  call  the  environment,  all  contribute  to  explain 
why  any  one  man  is  what  he  is.  To  review  some 
of  the  main  facts  about  the  influence  of  these 
factors  is  the  aim  of  this  chapter. 

THE  INFLUENCE   OF  SEX 

What  little  scientific  study  of  the  differences 
between  the  sexes  in  intellect  and  character  there 
29 


INDIVIDUALITY 

has  been,  tends  to  minimize  the  traditional  con- 
ception that  they  are  two  distinct  kinds  of  beings, 
never  understanding  one  another  and  requiring 
very  different  kinds  of  treatment.  On  the  con- 
trary, it  appears  that  if  the  primary  sex  charac- 
ters—  the  instincts  directly  related  to  courtship, 
love,  child-bearing,  and  nursing  —  are  left  out  of 
account,  the  average  man  differs  from  the  aver- 
age woman  far  less  than  many  men  differ  one 
from  another. 

In  no  trait  of  those  studied'  has  a  gap  been 
found  between  the  distributions  for  the  two  sexes. 
The  upper  extreme  of  one  sex  always  overlaps 
the  lower  extreme  of  the  other.  Some  girls  like 
to  fight  better  than  some  boys ;  some  men  are 
fonder  of  babies  than  some  women. 

The  overlapping  is,  in  most  of  the  traits  stud- 
ied, very  great.  For  example,  popular  belief  would 
perhaps  select  as  impressive  sex  differences  the 
greater  originality,  activity,  independence,  and 
frankness  of  the  male,  and  the  greater  emotion- 
ality, interest  in  personal  appearance,  and  reli- 
giousness of  the  female.  These  are  indeed  pro- 
bably among  the  largest  sex  differences.  But,  so 
30 


THE  INFLUENCE   OF  SEX 

far  as  is  known,  the  overlapping  in  these  cases  is 
approximately  as  shown  in  Figure  10.  Nearly  all 
women  are  more  original  than  the  least  original 
man,  and  probably  over  a  third  of  women  are 
more  original  than  the  average  man.  Nearly  all 
men  are  more  religious  than  the  least  religious 
woman,  and  probably  about  a  third  are  more  re- 
ligious than  the  average  woman. 


Fig.  io. 

In  a  study  by  indirect  methods,  whose  results 
therefore  are  somewhat  insecure,  Heymans  and 
Wiersma  found  as  the  greatest  difference  be- 
tween men  and  women  that  in  the  relative 
strength  of  the  interest  in  things  and  their  me- 
chanisms (stronger  in  men)  and  the  interest  in 
persons  and  their  feelings  (stronger  in  women). 
The  difference  is  a  trifle  greater  than  that  shown 
in  Figure  II.  Other  differences  not  so  large  are 
31 


INDIVIDUALITY 

that  being  a  man  tends  to  make  an  individual 
more  vigorous  in  movement,  more  athletic  and 
noisy,  more  independent,  less  sensitive  to  slight 
outside  stimuli,  less  efficient  in  perceiving  small 
details,  more  often  color-blind,  a  trifle  less  quick 
to  memorize,  less  shy  and  conscientious,  lazier 
and  fonder  of  games  of  skill,  mental  or  bodily, 
less  emotional,  less  eager  for  change,  quicker  in 
recovery  from  grief,  and  less  impulsive. 


Fig.  ii. 

The  prevailing  overestimation  of  maleness  and 
femalenessas  determinants  of  intellect  and  char- 
acter is  probably  due  to  two  causes.  In  the  first 
place,  literary  presentations  of  the  human  nature 
of  men  and  women  have  been  concerned  largely 
with  men  and  women  in  courtship,  love,  and  par- 
enthood. It  is  just  in  these  affairs  of  life  that  the 
sexes  do  show  the  greatest  mental  differences. 

Ifi  the  second*  place,  outside  of  courtship,  love, 
32 


THE  INFLUENCE  OF  RACE 

and  parenthood,  the  sexes  have  been  most  often 
compared  in  the  persons  of  their  most  eminent 
representatives.  Such  a  comparison  is  unfair  for 
the  sexes  as  wholes,  because  the  male  sex  is  the 
more  variable,  so  that  even  though  the  average 
man  is  inferior  to  the  average  woman  in  a  given 
trait,  the  best  men  in  it  may  be  above  the  best 
women.  So  in  music  and  literature,  although  the 
experience  of  schools  and  life  shows  women  in 
general  to  be  not  inferior  to  men,  the  greatest 
achievements  have  been  by  men.  The  greatest  •"" 
scientists,  poets,  painters,  and  musicians  have 
been  more  frequently  males  for  the  same  reason 
that  idiots  are  more  often  males. 

Sex,  then,  though  a  real  influence,  is  not  so 
great  an  influence  in  making  individuals  differ  as 
has  been  supposed.  Many  traits  are  practically 
uninfluenced  by  it.  The  variations  within  one 
sex  are  not  very  much  less  than  the  variations 
amongst  men  and  women  together. 

THE  INFLUENCE  OF  RACE 

Differences  in  remote  ancestry  or  race  account 
for  a  very  large  percentage  of  the  differences 
33 


INDIVIDUALITY 

found  amongst  men,  if  we  consider  both  their 
direct  effect  upon  original  nature  and  their  indi- 
rect effect  through  the  differences  in  training 
which  commonly  parallel  them.  Even  if  we  dis- 
regard the  past  and  confine  observation  to  the 
differences  amongst  living  men,  race  directly  and 
indirectly  produces  differences  so  great  that 
government,  business,  industry,  marriage,  friend- 
ship, and  almost  every  other  feature  of  human  in- 
stinctive and  civilized  life  have  to  take  account 
of  a  man's  race. 

But  the  effective  differences  between,  say,  the 
modern  European,  Chinese,  and  Negro  are,  in  the 
first  place,  in  part  physical.  It  is  not  the  Negro's 
soul  but  his  body  that  is  despised  by  many  of 
those  who  despise  him.  The  European  looks  like 
a  foreign  devil  to  the  Chinese.  The  white  man 
does  not  boast  of  his  intelligence  or  virtue,  but 
thanks  God  that  at  all  events  he  is  a  white  man. 

In  the  second  place,  clothes,  coiffure,  physical 
habits,  and  all  the  showy  but  trivial  expressions 
of  intellect  and  character  in  customs,  ceremonies, 
and  manners,  give  an  impression  of  fundamental 
unlikeness  that  is  quite  out  of  proportion  to  the 
34 


THE  INFLUENCE  OF  RACE 

real  facts.  The  Quakers  were  outlawed  largely 
because  they  kept  their  hats  on  !  A  Chinese 
must  be  a  queer  beast,  since  he  wears  a  pig-tail ! 
The  Hottentot,  poor  creature,  knows  no  better 
than  to  go  naked ! 

For  rational  control,  it  is  necessary  to  reach 
the  real  differences  in  intellect  and  character, 
unmagnified  and  undistorted.  Further,  it  is  de- 
sirable to  separate  off  sharply  the  direct  effect 
of  racial  differences  upon  original  natures  from 
their  indirect  effect  through  the  different  civili- 
zations or  cultures  which  happen  to  accompany 
them.  The  influence  of  the  latter  belongs  prop- 
erly under  the  influence  of  differences  in  the  en- 
vironment, and  will  be  omitted  from  considera- 
tion here. 

If  the  original  mental  natures  of  a  hundred 
Negroes,  Chinese,  Igorots,  and  Jews  were  given 
similar  bodily  externals  and  brought  up  under 
the  same  environment,  would  they  differ  more 
than  would  a  hundred,  all  Negroes  or  all  Chin- 
ese ;  and  if  so,  how  much  more  and  in  what  ways  ? 
That  is  the  present  question. 

It  is  a  pity  that  so  important  a  question,  by 
35 


INDIVIDUALITY 

the  answer  to  which  the  treatment  of  the  so- 
called  lower  by  the  so-called  higher  races  and 
the  treatment  of  the  latter  by  one  another  should 
be  largely  guided,  can  be  only  so  imperfectly  an- 
swered. It  is  literally  true  that  we  know  how  to 
breed  and  train  plants  far  better  than  we  know 
how  to  breed  and  train  men  for  important  traits 
of  human  nature.  Of  the  detailed  significance  of 
the  heredity  belonging  to  each  of  the  races  and 
sub-races  of  men,  little  or  nothing  is  known.  I 
can  only  illustrate  the  attitude  which  a  student 
of  the  topic  should  take  and  the  general  direc- 
tion in  which  the  truth  may  be  expected  to  lie. 
This  will  be  done  in  the  case  of  racial  differences 
in  general  intellect. 

The  first  fact  to  note  is  that  racial  differences 
in  original  nature  are  not  mere  myths.  For  ex- 
ample, the  colored  pupils  in  the  public  high 
schools  of  New  York  City  represent  probably  at 
least  as  good  a  selection  intellectually  from  the 
offspring  of  Negroes  and  Negro-white  crosses 
as  do  the  white  pupils  from  the  offspring  of  pure 
white  matings.  Any  superiority  of  the  white  to 
the  colored  pupils  is  almost  certainly  equaled 
36 


THE  INFLUENCE  OF  RACE 

by  the  difference  between  the  white  race  and  the 
Negro  race.  Yet  the  white  pupils  are  demonstra- 
bly superior  in  scholarship,  as  shown  in  Figure  12. 


1 

: 

1 
1 

1 

1 

1 
1 

1 

1 

1 

1 

1 
1 

M 

1 

1 

1 

• 

i 

1 

— 1 

20 


40 


60 


80 


100 


Fig.  12.  The  Relative  Frequencies  of  Different  Marks  in  the  High 
School  in  the  cases  of  White  Pupils  (continuous  line)  and  Colored 
Pupils  (broken  lines). 

The  differences  in  the  environment  do  not  seem 

at  all  adequate  to  account  for  the  superiority  of 

37 


INDIVIDUALITY 

the  whites.  To  take  the  one  other  case  of  meas- 
urements of  the  intellectual  capacities  of  different 
races,  Woodworth  found  that  the  best  of  the 
Negritos  and  reputed  Pygmies  just  reached  the 
average  European  in  a  simple  test  of  practical 
intellect. 

The  second  fact  to  note  is  that  the  differences 
in  intellect  due  to  race,  though  real,  are  in  gen- 
eral small.  In  the  test  by  Professor  Woodworth, 
just  mentioned,  only  small  differences  were  found 
between  the  Europeans  and  Indians,  Eskimos, 
Ainus,  Filipinos,  and  Singhalese. 

This  may  seem  irreconcilable  with  the  testi- 
mony given  by  the  history  and  present  status  of 
races.  If  racial  achievement  were  a  fair  measure 
of  intellect,  there  would  be  a  real  contradiction. 
But  achievement  is  a  measure  of  ability  only  if 
conditions  are  equal.  Two  important  conditions 
are  the  size  of  the  racial  group  and  its  communi^. 
cation  with  other  races.  A  small  race,  though  of 
equal  average  intellect  with  a  larger  race,  has 
not  so  great  a  probability  of  generating  an  ex- 
treme variation,  — a  man  of  extraordinary  ability, 
whose  discoveries  and  practices  uplift  all  who  can 
38 


THE  INFLUENCE  OF  NEAR  ANCESTRY 

learn  or  imitate  them.  An  isolated  race  in  the 
same  way  loses  the  means  of  progress  which 
come  from  borrowed  ideas  and  practices. 

The  third  fact  of  importance  is  the  overlap- 
ping. The  superiority  of  a  race  does  not  mean 
the  superiority  of  all  its  members  to  all  those  of 
the  other  race.  That  never  happens;  and  ordi- 
narily the  two  distributions  overlap  for  nine 
tenths  of  their  extent  along  the  scale.  Even  when 
the  average  of  one  race  is,  say,  ten  percent  more 
gifted  than  the  average  of  another,  there  will  still 
be  about  nine  out  of  ten  of  the  inferior  race  who 
will  surpass  the  worst  representative  of  the  su- 
perior race,  and  about  four  out  of  ten  who  will 
surpass  the  average  man  of  the  superior  race. 
There  is,  then,  hardly  a  more  stupid  way  of  get- 
ting individuals  of  superior  original  nature  than 
to  choose  them  by  race.  The  variation  of  original 
individuality  within  any  one  race  is  too  wide. 

THE  INFLUENCE  OF  NEAR  ANCESTRY 

Within  any  one  of  the  larger  groups  that  we 
call  races  there  are  many  strains  or  "lines,"  so 
that,  as  every  one  sees  in  the  case  of  physical 
39 


INDIVIDUALITY 

traits,  individuals  of  the  same  sex,  race,  and  train- 
ing still  differ  widely.  The  same  is  true  of  traits 
of  intellect  and  character.  In  them  also  individ- 
uals of  the  same  sex  and  race  differ  in  ways  and 
to  degrees  that  differences  in  training  cannot 
account  for.  As  will  be  shown  later,  the  exact 
dividing  line  between  the  influence  of  inheritance 
and  the  influence  of  environment  or  training  is 
subject  to  dispute,  but  every  one  who  has  inves- 
tigated the  facts  carefully  admits  that  the  former 
has  some  influence.  Mental  and  moral  inherit- 
ance from  near  ancestry  is  a  fact. 

A  human  being  develops  from,  and  in  his  ori- 
ginal nature  is,  an  ovum,  or  germ-cell  from  the 
mother,  fused  with  a  sperm,  or  germ-cell  from 
the  father.  A  germ-cell  from  any  parent  is  always 
one  of  many  produced  by  that  parent.  These 
vary  amongst  themselves,  so  that  the  possible 
heredity  from  any  one  parent  is  far  wider  and 
richer  than  his  own  nature.  A  man  gives  to  his 
children,  not  one  thing,  himself,  but  his  manifold 
germs.  With  respect  to  any  trait,  the  germs  from 
one  parent  vary,  however,  much  less  than  do  the 
germs  from  all  the  parents  in  that  race. 
40 


THE  INFLUENCE  OF  NEAR  ANCESTRY 

Let  us  call  that  element  or  constituent  of  a 
germ  which  tends  to  produce,  in  the  individual 
who  develops  from  it,  a  given  feature  of  intellect 
or  character,  that  feature's  determiner.  Then  the 
fact  just  mentioned  may  be  stated  in  this  form : 
Germs  from  the  same  individual  differ  in  their 
determiners  ;  germs  from  different  individuals 
of  the  same  race  differ  still  more ;  germs  from 
individuals  of  different  races,  still  more. 

Inheritance  is  at  bottom  a  matter  of  the  rela- 
tions of  germs  one  to  another.  A  parent  resem- 
bles his  offspring  because  the  germ  that  produced 
him  produced  also  the  germs  that  produce  them. 
He  differs  from  his  offspring  and  they  differ 
among  themselves  for  the  same  reason.  The 
difference  is  due  to  the  fact  that  germs  produced 
by  one  germ  vary.  The  likeness  is  due  to  the 
fact  that  they  vary  less  than  germs  produced  by 
many. 

Our  inferences  about  heredity,  however,  have  to 
be  made  from  the  resemblances  and  differences 
of  the  individuals  who  develop  from  the  germs. 
The  study  of  mental  and  moral  heredity  is  thus 
the  study  of  the  greater  resemblance  or  less 
4i 


V 


INDIVIDUALITY 

difference  of  related  than  of  unrelated  individ- 
uals. 

The  measurements  of  the  influence  of  near  an- 
cestry upon  individuality  have  naturally  taken 
the  form  of  measurements  of  the  greater  resem- 
blances of  related  individuals,  rather  than  of 
the  greater  differences  of  unrelated  individuals. 
Samples  of  the  results  obtained  are  the  follow- 
ing: Call  the  average  likeness  of  two  persons 
of  the  same  sex  and  race,  but  not  near  kin,  zero. 
Call  perfect  similarity  I.  Then  the  resemblance 
of  father  to  son  in  general  intellect  and  also  in 
moral  worth  is,  according  to  Woods,1  about  .4. 
The  resemblance  of  brother  to  brother  or  sister 
in  various  mental  traits  is,  according  to  Pearson, 
about  .5.  The  resemblance  of  twins  in  ability  to 
add  and  multiply,  in  finding  the  misspelled  words 
in  a  passage,  and  in  other  mental  tests  is  about  .8. 

It  would  be  too  long  a  task  to  rehearse  the 
evidence  from  which  it  appears  that  these  resem- 
blances are  due  only  slightly  to  resemblances  in 
home  training.  Sample  arguments  are  the  follow- 

1  Allowance  being  made  for  certain  facts  not  taken  account 
of  by  Professor  Woods  himself. 
42 


THE  INFLUENCE  OF  NEAR  ANCESTRY 

ing:  Twins  are  found  to  grow  no  more  alike 
from  nine  to  fourteen,  in  spite  of  the  fact  that 
any  influence  home  training  may  have  upon  abil- 
ity to  add,  multiply,  and  the  like  should  be  far 
greater  after  so  much  longer  action.  They  are 
found  to  be  as  much  alike  in  finding  misspelled 
words  or  giving  the  opposites  of  words  as  in  add- 
ing or  multiplying,  though,  presumably,  home 
training  should  count  more  in  the  latter.  Also  N. 
the  home  training  of  twins  does  not  seem  to  be 
very  much  more  constant  than  that  of  two  chil- 
dren of  the  same  family,  two  or  three  years  apart 
in  age ;  but  the  resemblance  is  twice  as  great. 

On  the  whole,  intellectual  and  moral  individu- 
ality seems  to  be  determined  to  a  very  large  ex- 
tent in  the  germs.  If  all  human  beings  were  given 
exactly  the  same  training,  subjected  to  exactly 
the  same  influences  from  the  time  of  their  con- 
ception, they  would  still  differ  widely.  Hygiene, 
medicine,  education,  and  all  social  forces  have  to 
reckon  with  original  differences  in  men.  Their 
aims,  means,  and  methods  must  be  adapted  to  fit 
not  one  nature,  but  many. 


43 


INDIVIDUALITY 

THE  INFLUENCE  OF  EDUCATION 

The  intellect  and  character  given  to  an  indi- 
vidual by  sex,  race,  and  near  ancestry  furnish 
the  starting  point  for  the  general  education 
which  he  gets  from  the  fortunes  of  life  and  the 
special  education  which  society  prescribes  for 
his  and  its  own  good.  Sometimes  these  environ- 
mental forces  bring  him  into  conformity  with 
others,  rounding  off  the  corners  of  his  individual- 
ity to  make  it  more  like  the  type:  in  other  cases 
the  environment  increases  initial  differences  and 
adds  to  the  total  variety  of  human  nature.  To 
what  extent  the  differences  that  come  to  exist 
amongst  individuals  are  to  be  attributed  to  dif- 
ferences in  their  nurture,  is  known  uncertainly, 
if  at  all.  I  shall  attempt  only  to  show  the  atti- 
tude a  thinker  must  take  toward  the  general 
question. 

There  is  no  doubt  that  differences  in  home, 
school,  books,  friends,  political  status,  and  the 
like,  may  cause  differences  in  the  intellect  and 
character  which  a  man  comes  to  possess,  —  in  his 
eventual  nature.  Two  identical  original  natures, 
44 


THE  INFLUENCE  OF  EDUCATION 

if  brought  up  in  1900  b.  c.  and  1900  a.  d.,  or  in 
Berlin  and  Pekin,  would  result  in  very  different 
eventual  natures.  The  Japanese  of  to-day  are 
probably  almost  or  quite  identical,  in  original 
nature,  with  their  great-grandfathers.  All  or 
nearly  all  of  the  differences  between  the  two 
groups  are  attributable  to  differences  in  environ- 
ment. Any  man's  individuality  is  determined  in 
large  measure  by  his  language,  occupation,  reli- 
gion, customs,  and  ideas.  These  again  are  deter- 
mined in  large  measure  by  his  nurture. 

But  the  influence  of  the  environment  is  sub- 
ject to  two  important  limitations.  Any  environ- 
mental force  has  far  less  effect  if  it  vsr-avoidable. 
If  a  boy  born  in  China  can,  if  his  nature  suffi- 
ciently impels,  go  to  a  modern  school,  the  influ- 
ence of  the  old-fashioned  Chinese  schools,  even 
though  they  outnumber  the  modern  schools  a 
hundred  to  one,  is  far  less  than  if  they  are  the 
unavoidable  form  of  education. 

If  the  custom  of  slavery  is  universal,  men  who 
are  by  original  nature  just  and  humane  will  in- 
humanly deprive  the  babies  born  in  slavery  of 
common  human  rights.  But  if  the  custom  is  called 
45 


INDIVIDUALITY 

in  question  at  all,  so  that  the  force  of  society's 
approval  of  it  is  avoidable,  — if  a  man  can  flee  in 
fact  or  in  thought  to  the  company  of  those  who 
distrust  slavery,  —  then  the  effective  force  of 
that  custom  is  enormously  weakened.  A  man 
may,  in  respect  to  it,  determine  his  eventual  na- 
ture by  his  original  nature. 

Similarly,  before  any  alcoholic  beverages  were 
known,  no  man,  however  intemperate  his  origi- 
nal nature,  could  be  a  dipsomaniac.  But,  once 
total  abstinence  is  avoidable,  the  determination 
of  a  man's  behavior  toward  liquor  may  be  made 
largely  by  his  original  nature.  He  may  shut  his 
ears  to  all  tales  of  the  misery  caused  by  drink, 
may  not  attend  to  any  of  the  facts  which  would 
facilitate  abstinence,  may  respond  to  all  restrain- 
ing forces  by  neglect,  and  seek  out,  as  a  result 
of  the  inner  impulsion  of  his  inborn  make-up, 
the  rare  opportunities  for  alcoholic  intoxication. 

The  second  limitation  to  any  environmental 
force  is  that  it  acts  differentially,  the  result 
being  determined  by  the  original  nature  acted 
upon  as  well  as  by  the  force  itself.  Even  in 
those  who  do  not  avoid  it,  it  has  all  degrees 
46 


THE  INFLUENCE  OF  EDUCATION 

of  welcome.  Being  slaves  does  not  make  all 
men  slavish,  much  less  equally  slavish.  Evil 
communications  may  ennoble  the  manners  of 
some  men.  "  The  environmental  stimulus  ade- 
quate to  arouse  a  certain  power  or  ideal  or 
habit  in  one  man  may  be  hopelessly  inadequate 
to  do  so  in  another.  Washing  bottles  in  a  drug- 
shop  was,  if  a  common  story  is  true,  adequate 
to  decide  Faraday's  career  ;  and  the  voyage  on 
the  Beagle  is  reputed  to  have  made  Darwin  a 
naturalist  for  life.  But  if  all  the  youth  of  the 
land  were  put  to  work  in  drug-shops  and  later 
sent  on  scientific  expeditions,  the  result  would 
not  be  a  million  Faradays  and  Darwins,  or  even 
a  million  chemists  and  naturalists.  All  that  one 
man  may  need  to  be  free  is  a  vote ;  but  even  a 
long  education  in  self-direction  may  be  inade- 
quate for  another.  Being  told  a  few  words  suf- 
fices to  secure  the  habit  of  reading  in  one  child, 
while  the  child  beside  him  remains  illiterate  after 
two  years  of  careful  tuition.  The  amount  of 
stimulus  required  in  some  cases  is  so  infinitesi- 
mal that  the  power  seems  to  spring  absolutely 
from  the  man  himself.  In  other  men  no  agency 
47 


INDIVIDUALITY 

is  found  potent  enough  to  arouse  a  trace  of  the 
desired  result." 

As  a  result  of  these  limitations,  it  is  hard  to 
find  differences  between  one  and  another  man 
of  the  same  era  and  general  social  condition  that 
are  clearly  due  to  differences  in  training.  The 
great  scholar  is  not  made  by  attendance  at  a 
university ;  rather  his  own  nature  made  him 
seek  that  influence  scorned  by  so  many  others. 
Many  a  drunkard  remains  so  in  spite  of  fewer 
temptations.  Saloons  being  inaccessible,  he 
drinks  at  home  ;  whiskey  being  debarred,  he 
takes  to  "bitters"  or  patent  medicines;  one 
suspects  that  if  alcohol  did  not  exist,  he  would 
soon  discover  cocaine.  Each  nature  in  some 
measure  selects  its  own  environment,  and  each 
nature  may  get  from  an  environment  a  different 
influence,  so  that  the  relative  achievements  of, 
say,  the  boys  who  this  year  begin  school  in 
America,  will  probably  be  more  closely  parallel 
to  their  relative  original  talents  and  interests 
than  to  their  relative  advantages  in  home  and 
school  environment. 


Ill 

THE   SIGNIFICANCE  OF  INDIVIDUAL  DIF- 
FERENCES 

We  have  seen  that  individuals  differ  in  what- 
ever trait  of  intellect  or  character  is  examined. 
The  variations  from  the  ordinary,  common,  or 
typical  man  range  continuously  to  such  extreme 
conditions  as  appear  in  the  idiot  and  the  genius, 
or  Nero  and  Lincoln.  But  the  great  majority 
cluster  somewhat  closely  around  the  "  average 
man."  Clear  and  useful  divisions  into  separate 
classes  are  impossible  with  respect  to  either  the 
amount  of  some  single  trait  or  the  total  consti- 
tution of  the  mind. 

The  differences  that  characterize  men  of  the 
same  time,  country,  and  social  status  are  largely 
original,  determined  directly  by  the  germs  from 
which  the  individual  develops,  and  so  indirectly 
by  the  ancestry  from  which  he  springs.  Each 
original  nature  has  so  great  power  of  selecting 
and  avoiding  the  forces  of  social  and  educational 
49 


INDIVIDUALITY 

environment  that  the  fundamental  powers,  in- 
terests, and  ideals  of  such  men  are  largely  de- 
termined before  they  are  born.  Over  the  par- 
ticular connections  with  ideas  which  we  call 
knowledge,  and  the  particular  connections  with 
acts  which  we  call  skill,  training  has  greater 
power ;  and,  of  course,  unavoidable  differences 
in  training,  such  as  go  with  differences  between 
1700  and  1900,  England  and  China,  slave  and 
free,  are  far  more  potent. 

All  the  sciences  and  arts  of  controlling  hu- 
man nature  must  accept  the  original  variety  of 
human  nature  as  a  condition  for  thought  and 
action.  The  economist  must  not  consider  men 
as  all  seeking  with  steadfast  rationality  to  buy  as 
cheap  and  sell  as  dear  as  they  can.  The  religious 
worker  should  not  hope  to  arouse  uniformly  the 
same  sense  of  guilt  and  longing  for  justification 
to  which  he  and  his  intimates  testify.  The 
scholar  may  as  well  expect  all  men  to  be  pas- 
sionately eager  to  use  the  left  rather  than  the 
right  hand,  as  expect  them  to  prefer  linguistic 
or  mathematical  erudition  to  ignorance.  The 
teacher  who  has  not  learned  by  ordinary  experi- 
50 


SIGNIFICANCE  OF  INDIVIDUALITY 

ence  that  each  child  is  to  some  extent  a  separate 
problem,  demanding  for  his  best  interest  an  edu- 
cational theory  and  practice  to  fit  kim,  should 
learn  it  once  for  all  from  psychological  theory. 

Specialization  of  schools  is  needed  not  only  to  / 
fit  pupils  for  special  professions,  arts,  trades,  and 
the  like,  but  also  to  fit  the  schools  to  original 
differences  in  the  pupils.  Specialization  of  in- 
struction for  different  pupils  within  one  class  is 
needed  as  well  as  specialization  of  the  curriculum 
for  different  classes.  Since  human  nature  does 
not  fall  into  sharply  defined  groups,  we  can  lit- 
erally never  be  sure  of  having  a  dozen  pupils 
who  need  to  be  treated  exactly  alike. 

All  thought  and  action  will  be  more  reason- 
able and  humane  if  we  look  for  variety  in  men 
and  examine  each  nature  in  a  scientific  spirit  to 
learn  what  it  really  is,  instead  of  idly  judging  it 
by  some  customary  superstition.  For  example, 
the  most  pitiful  waste  and  unreason  in  human 
affairs  is  behavior  whereby  one  makes  himself 
suffer  to  secure  for  another  a  good  which  is  to 
the  other  a  nuisance  or  a  pain.  A  parent  who 
sacrifices  his  own  joys  to  protect  his  children 
51 


INDIVIDUALITY 

against  the  healthy,  beloved,  and  noble  struggles 
of  life ;  a  philanthropist  who  lessens  his  own 
welfare  to  teach  factory-workers  refinements, 
knowledge  of  which  can  only  embitter  their  in- 
ability to  secure  them  ;  a  religion  that  spends 
life  in  stimulating  the  fears  and  worries  of  men 
whom  fear  and  worry  will  never  lead  to  right 
living,  but  only  to  more  worry  and  fear,  —  in 
such  gratuitous  miseries,  false  diagnosis  of  hu- 
man hearts  is  prolific. 

The  most  necessary  elements  in  the  life  of 
reason  and  justice  are,  first,  an  awareness  of 
what  individual  human  natures  really  are  and 
really  want ;  and  then  an  appreciation  of  the  rela- 
tive worth  of  the  myriads  of  wants  thus  revealed. 
This  valuation  of  human  wants,  in  turn,  is  im- 
proved chiefly  by  knowing  what  they  are  and  how 
each  competes  or  cooperates  with  all  the  others. 
Only  in  proportion  as  such  a  science  of  the 
nature  and  behavior  of  individual  men  exists 
can  man  know  what  his  duty  is  or  know  how  to 
do  it. 


OUTLINE 

I.  THE  NATURE  OF  INDIVIDUAL  DIFFERENCES 

1.  Man's  life  a  double  series I 

2.  Men  differ  widely I 

3.  Common  traits  and  individual  differences     ...  2 

4.  The  complexity  of  single  mental  traits     ....  3 

5.  Individuals  differ  in  quality  and  quantity  of  traits  4 

6.  Qualitative  differences  really  differences  of  degree  5 

7.  A  man's  nature  is  a  compound  of  his  several  abilities  5 

INDIVIDUAL  DIFFERENCES  IN  SINGLE  TRAITS 

1.  Variation  can  be  found  in  every  human  trait     .     .     6 

2.  The  older  psychology  neglected  individual  differ- 

ences     7 

3.  Individual  differences  are  found  at  every  stage  of  life     7 

4.  Stature  of  American  boys  as  an  example      ...     8 

5.  The  distribution  of  a  trait  along  a  scale       ...   10 

6.  An  accurate  method  of  determining  common  ten- 

dency and  individual  variation 1 1 

7.  Casual  observation  notes   extreme,  odd,  exciting, 

and  desired  facts 11 

8.  Two   important    facts  at  variance  with    common 

opinion 12 

9.  Variations  in  a  single  trait  are  usually  continuous   13 
10.  Variations  usually  cluster  around  only  one  type     .  13 

II.  Individual  ability  best    expressed  by    numerical 

amounts 13 

12.  The  great  frequency  of  mediocrity  and  its  practical 

implications 16 

53 


OUTLINE 

13.  Wide  and  continuous  variations  call  for  versatile 

methods  of  treatment 18 

14.  The  need  for  both  absolute  and  relative  measures 

of  power 18 

INDIVIDUAL  DIFFERENCES  IN  COMBINATIONS 
OF  TRAITS 

1.  Thepossible  varieties  of  men  are  practically  infinite  19 

2.  The  futility  of  the  multiple-type  theory   ....  22 

3.  There    is   a  single    type    or   as    many    types    as 

individuals 25 

4.  The  supposed  principle  of  compensation  in  types 

is  discredited 26 

5.  A  large  amount  of  one   desirable  trait  increases 

probability  of  same  in  another 26 

6.  A  description  of  total  human  nature  is  unavoidably 

complex 27 

II.   THE  CAUSES  OF  INDIVIDUAL  DIFFERENCES 

1.  Human  peculiarities  are  a  result  of  natural  laws  29 

2.  Sex,  race,  family,  maturity,  and  environment  con- 

tribute        29 

THE  INFLUENCE  OF  SEX 

1.  Scientific  study  minimizes  traditional  conceptions 

of  sex  differences 29 

2.  The  upper  extreme  of  one  sex  greatly  overlaps  the 

lower  extreme  of  the  other       .....*..  30 

3.  Probably  a  third  of  one  sex  are  superior  to  the 

average  of  the  other  in  any  given  trait      .     .     .31 

4.  Specific  differences  between  men  and  women   .     .31 

54 


OUTLINE 

5.  Two  causes  of   the  popular  overestimation  of  sex 

differences 32 

6.  Literary  presentations  emphasize  the  greatest  sex 

differences 32 

7.  Comparisons  of  eminent  sex   representatives   dis- 

regard greater  variability  of  the  male     ....  32 

THE    INFLUENCE  OF  RACE 

1.  Remote   ancestry   explains   a  large  percentage  of 

differences 33 

2.  Effective  racial  differences  are  in  part  physical        .  34 

3.  Customs,  ceremonies,  and   manners   increase  the 

sense  of  racial  difference 35 

4.  Rational    control  requires  a  direct  study  of   real 

differences  in  intellect  and  character      .     .     .     .  35 

5.  Little  is  known  of  the  detailed  significance  of  racial 

heredity 36 

6.  Racial  differences  in  original  nature  are  not  mere 

myths 36 

7.  Differences  in  intellect  due  to  race  are  generally  small  38 

8.  The  superiority  of  a  race  does  not  imply  the  supe- 

riority of  all  its  members 39 

THE  INFLUENCE  OF  FAMILY 

1.  Mental  and  moral  inheritance  from  near  ancestry 

is  a  fact 39 

2.  The  possible  heredity  from  a  parent  is  far  wider 

than  his  own  nature 4° 

3.  There  is   greater  resemblance  of  related  than  of 

unrelated  individuals        41 

4.  The  degrees  of  resemblance  between  members  of 

the  same  family       42 

55 


OUTLINE 

5.  These  resemblances  are  clue  only  slightly  to  similar 

home  training 42 

6.  Hygiene,  education,  and  social  forces  must  reckon 

with  original  differences  in  men 43 

THE  INFLUENCE  OF  EDUCATION 

1.  Nurture  sometimes    restricts   and  sometimes   em- 

phasizes individual  qualities] 44 

2.  Many  differences    in    groups  are  attributable    to 

varying  environment         44 

3.  Any  environmental  force  has    less   effect  if  it  is 

avoidable 45 

4.  Environmental    forces    act    differentially,  original 

nature  being  a  selective  agent 46 

III.   THE  SIGNIFICANCE  OF   INDIVIDUAL 
DIFFERENCES 

1.  The  way  in  which  individuals  differ 49 

2.  The  differences  that  characterize  men  are  largely 

original 49 

3.  Social  control  must  accept  human  variation  as  a 

condition 5° 

4.  The  need  to  specialize  schools  and  instruction    .     .51 

5.  False  views  of  human  nature  lead  to  waste     .     .     .51 

6.  The  valuation  of  human  wants  rests  on  a  true  view 

of  human  nature 52 


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